带可更换式阻尼夹层的半通缝连梁抗震性能研究

The coupling beam is an important component of energy reduction in shear walls structure. The researchers pay close attention to the investigation on the energy reduction improvement of the coupling beam. The coupling beam with semi seam filled replaceable damping layer is the whole section beams of small span-depth ratio divided into the upper and lower beams and the middle part padded with viscoelastic damping material layer, which is facilitated to replace after the earthquake.The beam not only can effectively solve the problem of the great stiffness of the whole section beam with small span -depth ration, but also solve the problem that the reduction of the double coupling beam with straight-line joint. At the same time,it can also improve the ductility and energy reduction ability of the beam.At normal service condition, it can maintain the stiffness and bearing capacity in order to protect the shear wall. In the earthquake, according to the thought of the multi-defence system of earthquake-resistant, the damping layer and upper and lower coupling beam will dissipate and absorb the energy step by step so as to protect the shear walls.Through the low-cycle repetitive loading test, the seismic performance of the coupling beam will be studied in this project.The bending and shear bearing capacity calculation formula and seismic construction measures will be put forward from the pull rod - compressive bar model which simulate the un-elastic stress at local disturbance area in the reinforced concrete structure. Meanwhile, the mechanics contribution of damping laminated material should be considered comprehensively. Based on secondary development of the software ABAQUS, 3-D model will be established to conduct nonlinear analysis so that the load carrying capacity and the energy dissipation mechanism at different stage can be comprehended thoroughly. The results will benefit the anti-seismic performance of the high rise structures.

连梁是联肢剪力墙结构中重要的耗能构件，研究者们都致力于改善其耗能能力方面的研究。本项目提出的带可更换式阻尼夹层的半通缝连梁，即将小跨高比整截面连梁分成上下两根梁肢，中间加设黏弹性阻尼材料夹层，并对阻尼夹层进行模块化设计，以便于震后更换。该连梁可有效解决小跨高比整截面连梁刚度过大和全通缝连梁截面刚度削减过大的不足，而且延性和耗能能力突出。正常使用状态下能保持足够的刚度和承载能力并约束墙肢。地震作用时，阻尼夹层和上、下梁肢逐级减震耗能退出工作，从而保护墙肢。本项目拟通过低周反复加载试验研究其抗震性能；以拉杆-压杆模型模拟钢筋混凝土结构中局部扰动区的非弹性受力，综合考虑阻尼夹层材料的力学贡献，提出抗弯及抗剪承载力计算公式及抗震构造措施；基于有限元软件ABAQUS进行二次开发，建立三维有限元模型进行非线性分析，全面地了解连梁各组分在各个阶段的受力情况及其耗能机制。该研究成果将有助于高层结构的抗震。

连梁是联肢剪力墙结构抗震设防的第一道防线，在地震荷载作用下，保证连梁先于墙肢破坏，利用连梁梁端产生的塑性铰转动，消耗地震作用于建筑物的大部分能量，从而达到保护建筑物的目的。本项目提出半通缝连梁、带阻尼夹层半通缝连梁以及带新型截断式铅粘弹性阻尼器(TLVD)的连梁形式,并对提出的几种新型连梁形式的破坏形态与受力特征及延性、耗能等抗震性能及设计方法等一系列关键问题进行了研究，主要研究内容如下：1)通过半通缝连梁的拟静力试验，对半通缝连梁的裂缝发育、各类钢筋应变分布特征以及连梁破坏类型进行分析，揭示了半通缝连梁的破坏形态和受力特征，研究其在低周反复作用下的承载力、变形能力、延性及耗能能力的变化规律，并基于试验结果建立模拟该类型连梁受力性能的计算模型，全面了解其抗震性能。2）基于有限元软件ABAQUS建立三种不同连梁形式的单片双肢剪力墙结构数值模型，对结构的低周反复试验进行模拟，分析三种截面形式连梁的单片双肢剪力墙结构在低周往复荷载作用下的承载能力、耗能能力和延性。3）通过研究不同因素对半通缝连梁抗震性能的影响，通过数值试验数据进行回归分析，建立骨架曲线恢复力模型，对研究半通缝连梁的刚度退化规律，建立循环荷载作用下结构的恢复力模型。4）提出含铅阻尼夹层连梁，研究其延性、耗能能力、强度及刚度退化等抗震性能，找出影响该类连梁抗震性能的主要因素，并得出其影响规律。5）提出了一种新型截断式铅粘弹性阻尼器(TLVD)，用来改善小跨高比连梁的抗震性能，并建立三维有限元模型进行非线性全过程分析，了解各组分在各阶段的受力情况、耗能机制及抗震性能。总体而言，本项目提出的多种连梁形式，满足多道设防要求，并改善了普通连梁和双连梁在抗震性能上的不足。同时，新型的连梁形式，在震后具有可更换优点，便于震后及时修复，在高层建筑结构具有很好的应用前景。